Canon CANOSCAN D1230 series Service Manual page 39

CHAPTER 2
1) Interpolation Processing
When reading images at higher resolution, the one pixel output of the CCD is treated as two
image data in the horizontal scanning direction, and the one line output of the CCD is treated
as two image data in the vertical scanning direction, causing a reduced image quality. To
prevent the image quality reduction, interpolation processing is performed. Figure 2-16 shows
a change in image density by the interpolation processing.
A
A
Image
Density
1 pixel
Image
Density
1 pixel
2 - 16
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(A) B (B)
(A+B)/2 B (B+C)/2
Figure 2-16
©
2001 CANON INC. CANOSCAN D1230U/D2400U REV.0 MAR. 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
C (C) D
Interpolation processing
C (C+D)/2 D
Interpolation processing